Step 1. Get a USB to Serial Adapter (FTDI or Cypress are both good)
Step 2. Get an ESP8266 board (this project is based on the -01 version of the board)
Step 3. Get / build a board or breadboard a setup to handle the level translation between the USB port (5V0) and the ESP8266 (3V3) *this is what this project basically does, plus a few other interesting things* :)
Step 4. Get NodeMCU repo from Github (the whole thing)
Step 5. Flash the ESP8266 with NodeMCU (be sure to have GPIO0 low when you reset the device, prior to programming...must be low until programming starts)
Step 6. Download ESPlorer from http://esp8266.ru/esplorer
Step 7. Load an example LUA file containing NodeJS to the device by ESPlorer and Run
Voila. Life is good. Unless it isn't. If that's the case, make comments.